In the following post uses the VSTS release API to get all the work items associated with a release: VSTS find workitems between two releases
It uses the following call:
Most of the REST APIs are documented here : Visual Studio Team Services REST API Reference
However some related REST APIs are not documented. For these REST APIs we can use tools such as Fiddler or directly press F12 - network
in Chrome to track them.
Based on my test, no such a REST API can directly retrieve the compared commits from Release. Actually the different commits are retrieved by several REST APIs, get information from corresponding changesets then compare them...
So, if you want to get the different commits with REST API, you need to retrieve the changeset ID from previous release and the changeset ID in current release. then compare them.
e.g:
POST : https://{account}.visualstudio.com/{project}/_api/_versioncontrol/history?api-version=5.0-preview.1
Request Body:
{"repositoryId":"","searchCriteria":"{\"itemPaths\":[\"$/0522TFVCScrum/PS\"],\"fromVersion\":\"180\",\"toVersion\":\"183\",\"top\":50}"}